Let G=(V,E) be an undirected graph and c:E->{-1,+1} a conservative cost function. We show that the problem of determining the maximum number of edges whose cost can be changed from 1 to -1 without violating the conservativeness of c is NP-complete. A similar result about directed graphs is also proved.
Bibtex entry:
@techreport{egresqp-11-06,
AUTHOR | = | {B{\'e}rczi, Krist{\'o}f and B{\'e}rczi-Kov{\'a}cs Ren{\'a}ta, Erika}, |
TITLE | = | {A note on conservative costs}, |
NOTE | = | {{\tt egres.elte.hu}}, |
INSTITUTION | = | {Egerv{\'a}ry Research Group, Budapest}, |
YEAR | = | {2011}, |
NUMBER | = | {QP-2011-06} |